A telephone network is a

telecommunications Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electronic means, typically through cables, radio waves, or other communication technologies. These means of ...

network that connects

telephone A telephone, colloquially referred to as a phone, is a telecommunications device that enables two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most ...

s, which allows

telephone call A telephone call, phone call, voice call, or simply a call, is the effective use of a connection over a telephone network between the calling party and the called party. Telephone calls are the form of human communication that was first enabl ...

s between two or more parties, as well as newer features such as fax and

internet The Internet (or internet) is the Global network, global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a internetworking, network of networks ...

. The idea was revolutionized in the 1920s, as more and more people purchased telephones and used them to communicate news, ideas, and personal information. During the 1990s, it was further revolutionized by the advent of computers and other sophisticated communication devices, and with the use of dial-up internet. There are a number of different types of telephone network: * A

landline A landline is a physical telephone connection that uses metal wires or optical fiber from the subscriber's premises to the network, allowing multiple phones to operate simultaneously on the same phone number. It is also referred to as plain old ...

network where the telephones must be directly wired into a single

telephone exchange A telephone exchange, telephone switch, or central office is a central component of a telecommunications system in the public switched telephone network (PSTN) or in large enterprises. It facilitates the establishment of communication circuits ...

. This is known as the

public switched telephone network The public switched telephone network (PSTN) is the aggregate of the world's telephone networks that are operated by national, regional, or local telephony operators. It provides infrastructure and services for public telephony. The PSTN consists o ...

or PSTN. * A

wireless network A wireless network is a computer network that uses wireless data connections between network nodes. Wireless networking allows homes, telecommunications networks, and business installations to avoid the costly process of introducing cables int ...

where the telephones are mobile and can move around anywhere within the coverage area. * A private network where a closed group of telephones are connected primarily to each other and use a gateway to reach the outside world. This is usually used inside

companies A company, abbreviated as co., is a legal entity representing an association of legal people, whether natural, juridical or a mixture of both, with a specific objective. Company members share a common purpose and unite to achieve specifi ...

and

call centre A call centre ( Commonwealth spelling) or call center ( American spelling; see spelling differences) is a managed capability that can be centralised or remote that is used for receiving or transmitting a large volume of enquiries by telephone ...

s and is called a

private branch exchange A business telephone system is a telephone system typically used in business environments, encompassing the range of technology from the key telephone system (KTS) to the private branch exchange (PBX). A business telephone system differs from ...

(PBX). * Integrated Services Digital Network (ISDN) Public telephone operators (PTOs) own and build networks of the first two types and provide services to the public under license from the national government. Virtual Network Operators (VNOs) lease capacity wholesale from the PTOs and sell on

telephony Telephony ( ) is the field of technology involving the development, application, and deployment of telecommunications services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is ...

service to the public directly.

References

Telecommunications infrastructure {{telecomm-stub

See also

References